Final answer:
The typical speed limit in areas without a posted sign in residential, business, and school zones is approximately 31 miles per hour (50 km/h). It's essential to observe these limits for safety and to avoid legal penalties, as the enforced speed limit (de facto) may offer only a minor leeway above the legal limit (de jure).
Step-by-step explanation:
In areas without a speed limit sign, the speed limit in school, business, and residential areas is typically set by local or state law. For instance, a common speed limit for residential areas is around 50 kilometers per hour, which is approximately 31 miles per hour. It is important to note that the actual, or de jure, speed limit is what is legally posted and should be followed.
However, the de facto speed limit refers to the speed at which enforcement action, such as being pulled over by police, may occur, which might offer a slight leeway above the posted limit. Still, it is crucial for safety and legal reasons to adhere to the posted speed limits or standard limits where they are not posted.
Moreover, traffic signals and signs serve to ensure that vehicles slow down in congested or potentially hazardous areas such as intersections, school zones, and business districts. When encountering an intersection, drivers should also be aware that they need to cross it safely without speeding, considering the distance and time needed for pedestrians to cross as well. In absence of posted signs, the default speed limit should be observed, especially in residential and densely populated urban areas.